Central Arms is a trade name used by Crescent Firearms on guns made for Shapleigh Hardware of St. Louis. They are good quality, low priced guns that were geared toward the "working class".
The only extractors I can locate are for the 12 gauge guns. Numrich Gun Parts has them. If you have the broken parts, it may be possible to weld them back together or have one made for your gun. It may also be possible to modify the 12 gauge part to fit.
You can fire the gun without the extractor, all it does is push the empty out.
I saw your question on the H&R shotgun and you were given an incorrect answer. Numrich sells the barrel studs. They need to be welded to the barrel. The following link will take you to them.
They are changing to a new system and on some there is no way to rate. In the future there will be 5 choices for rating, the top 3 are good and the other 2 are like a negative. I did get credit for them. Thank you very much!
On semi auto AK-47's the trigger acts as the sear. The disconnector is the piece that goes inside the trigger. It holds the hammer back until the the trigger is released and then the trigger catches the hammer notch. On a full auto, there is a separate sear and a hammer retarder which holds the hammer back to allow the bolt to close. All 2 stage triggers work the same way.
If you need anything else, you know where to find me. I am extremely busy in the shop, but check in a few times each day.